1. Field of the Invention
The present invention relates to a reflection type optical sensor device, and more particularly, to a reflection type optical sensor device that may integrate, on a single chip, a semiconductor light source and a photo-detection element that are used for a reflection type optical sensor device, in order to more accurately detect the light.
2. Description of the Related Art
Generally, a reflection type optical sensor includes a light emitter and a light receiver on the same side of an object for detection. The existence of the object may be detected when the light emitted from the light emitter is reflected from the surface of the object and is received by the optical receiver.
Known reflection type optical sensors include a light-emitting diode and an optical receiver installed within a cavity. However, the light of the light-emitting diode may cause an inaccurate detection due to its low intensity and excessive crosstalk.
Accordingly, a reflection type optical sensor using a vertical cavity surface emitting laser (VCSEL) is currently being used instead of the light-emitting diode.
FIG. 1 is a diagram illustrating a reflection type optical sensor device according to a related art. As a known patent applying the reflection type optical sensor device of FIG. 1, disclosed is the Korean Patent Publication No. 10-2007-0088573, titled “combined laser transmitter and photo-detector receiver package”.
Referring to FIG. 1, the known reflection type optical sensor device 100 includes a reflection type sensor package with a first cavity 120 and a second cavity 130 in order to detect the existence and absence of an object 110. In order to emit the light, a VCSEL 140 is located within the first cavity 120, and an optical receiver 150 is located within the second cavity 130.
In this instance, the optical receiver 150 is constructed to receive at least one portion of the light that is emitted from the VCSEL 140 and is reflected from the object 110. When the reflected light exceeds a predetermined threshold, it is determined that the object 110 exists.